The nursery business of growing plants from seeds and nurturing the plants until they are large enough for sale is rapidly increasing in urban areas where homeowners are interested in decorating their homes and lawns with growing plants, including herbs, grasses, shrubbery, trees, vegetables, and a variety of ornamental individual plants. The business requires someone to begin the process by planting seeds, cuttings, or the like in small containers, perhaps transferring the small seedlings to intermediate sized pots, and eventually sell the potted plant or cut it to be sold as individual flowers, branches, or the like. The usual place of beginning is in a cell of a tray containing 50-100 or more cells arranged in checkerboard fashion of vertical columns and horizontal rows, perhaps of a lightweight rupturable material that may be biodegradable such that the seedling and its cell may be planted. In other optional systems the tray is intended to be reusable, and this requires a step of removing the plug of earth and its seedling from the growth cell in the tray. It is at this step that the present invention finds its utility.
Removal of seedlings from a reusable tray has for many years been chiefly a task for humans. However, some inventors have devised machinery to do this job. The principle problem has been to remove the seedling and a plug of earth in a unit that is strong enough to be handled without losing the earth plug and without damage to the roots and the vegetation. These problems have led to the design of cells that taper from narrow at the bottom to wider at the top of the earth plug, thus making it easier to remove a solid plug. Furthermore, cells are now made with large holes in the center of the bottom wall so as to permit a plunger to enter the hole from outside the bottom and to push the plug of earth and the seedling upwardly out of the cell. Both of these design features are now standard state-of-the-art, and are expected to be used with the apparatus of this invention. There is room for much improvement over the early machines for removing seedlings from trays, and it is believed that this invention will advance the art considerably.
It is an object of the invention to provide an improved seedling handling machine. It is another object of this invention to provide an apparatus for continuously removing seedlings from growth trays and transport the seedlings individually to another location for further handling, e.g., for planting in the ground by using the apparatus described and claimed in my U.S. Pat. No. 4,788,029. Still other objects will become apparent from the more detailed description which follows.